Monday, June 28, 2010

Mental models matter in product design

At the June meeting of the UX Group of Waterloo Region June Meeting last week we had a fine presentation from Amy Gill on her research into think aloud usability assessments, in which users are asked to verbalize their thoughts while using a product and performing one or more tasks. There was a lot of great discussion on the topic and on related issues, as many folks who were in the room have experience running test sessions with users.

I’ve had experience on both sides of a test, though not everyone thinks that UX professionals make for good test subjects. When the discussion touched on mental models, I was reminded of an experience that I had as a test subject for a software product.

On one of the first screens that I saw, there was a reference to David Allen’s Getting Things Done and how the product being tested related to it. As I have used GTD for many years, that immediately set my expectations and a particular model snapped into place in my mind. That model was the lens through which I looked at the product for the rest of the session, during which I struggled somewhat with fully grasping the product and how to use it. After the session ended, there was some discussion, and it turned out that the GTD reference was not intended to have been there, and that the product is not meant to be a GTD implementation. Such was the power of the wrong mental model, though, that I simply could not see the product in any other way, despite many other cues in the user interface that contradicted my model.

While the details of interaction design, visual design, and information architecture all matter, if the resulting product is conceptually unclear or leads to an inappropriate mental model for users, the product will be challenging to use. It’s critical to get the mental model right.